Squib connector for automotive air bag assembly

ABSTRACT

A squib connector for automotive air bag assemblies is disclosed. The squib connector includes a connector position assurance mechanism (CPA) to ensure that the connector is properly connected to the squib receptacle and a connector lock assurance mechanism (CLA) to ensure that the connector is locked into the receptacle. The connector includes a pair of terminals each having contact beams which provide at least four points of contact with the terminals of the squib. Primary and secondary terminal latches ensure that the terminals are firmly retained within the connector. Wire strain relief is provided by placing an intentional bend in the wires and rounding the end of the connector where the wires enter.

FIELD OF THE INVENTION

This invention relates to the field of connectors and more particularlyto squib connectors for automotive air bag assemblies.

BACKGROUND OF THE INVENTION

Supplemental inflatable restraints or air bag assemblies are becomingincreasingly common as a safety device in vehicles throughout the world.The assembly comprises an inflatable canister located in the steeringcolumn or the passenger-side dashboard. Upon a sufficiently greatdeceleration, the canister is inflated by an explosive device known as asquib which contains a gun powder-based material. The squib is firedelectronically upon an electrical signal sent via wires from adeceleration sensor in the vehicle. The wires are attached to the squibvia a squib connector which plugs into a receptacle in the squib and istypically retained therein by a friction fit.

Prior art squib connectors are shown in U.S. Pat. Nos. 5,314,345 and5,178,547. The squib connector of the U.S. Pat. No. 5,314,345 is anexample of a prior art connector which is frictionally fitted within thesquib receptacle and must be pried out, which risks damaging theconnector. In addition, this connector includes a locking clip attachedwith a tether to the connector. This locking clip is somewhat difficultto align, because it must be done visually. Additional commerciallyavailable prior art squib connectors include Models UT12367, UT13308,and UT13309 from Morton International.

The integrity of the wire connection to the squib must be maintained toensure that the squib will fire when the deceleration sensor senses asufficiently great deceleration and sends a signal to the squib. Thesquib connector is particularly subject to failure due to handlingduring manufacture of the vehicle and during replacement of a spent airbag assembly. The connector must keep out dust and moisture andwithstand the vibrations, shocks, and temperature extremes associatedwith operation of the vehicle in which the connector is located. Thus, aneed exists for a robust squib connector.

SUMMARY OF THE INVENTION

The present invention provides a squib connector having a connector bodysized to fit within an initiator receptacle of a squib. A pair of boxterminals is located internally of the connector body for electricalcommunication with the initiator pins in the squib receptacle. The squibconnector also includes a cover and a combination connection positionassurance member or CPA and connector lock assurance member or CLAoverlying the cover. A pair of wires from the deceleration sensor enterthe connector body through a space between the cover and the body. Awire crimping device in electrical communication with the box terminalfixes the wires to the box terminal.

The connector provides primary strain relief for the entering wires byintentionally kinking or bending the wires at the point where they enterthe connector body. Secondary strain relief is provided by forming theend of the cover with a curved surface to prevent the wires from bendingtoo much.

Each box terminal includes two contact beams which are bent to extendupwardly within the box and biassed into contact with opposite sides ofthe initiator pins of the squib receptacle. Each contact beam is curvednear its free end to wrap around the initiator pin to provide at leastfour points of contact per box terminal. A conductive strip is providedon each contact beam in the area where the beam contacts the initiatorpin. A lubricating material formed from the same material as theconductive strip is also provided on each contact beam to reducefriction during insertion to the initiator pin between the two opposedbeams.

Each box terminal is held within the connector body by a primaryterminal latch and a secondary terminal latch. The primary latch isintegrally formed in the connector body by a first arm configured toseat against a top edge of the box of an associated box terminal. Thesecondary latch is integrally formed in the connector body by a secondarm configured to seat against an end of a louver formed in one wall ofthe associated box terminal. Once in place, each box terminal is heldsecurely between the first and second terminal latches and a floor ofthe connector body. The combination of the primary and the secondaryterminal latches increases resistance to pulling the terminal out of thebody.

The CPA/CLA is hinged to the connector body with a hinge pin integrallymolded to the CPA/CLA to form a unitary structure. The CPA/CLA includesa connector position assurance mechanism to ensure that the connector isproperly positioned on the initiator pins. Latching beams are formed onopposed sides of the connector body. A latching lug is formed near thebase of each associated latching beam for mating with a recess in theinitiator receptacle. To remove the connector from the receptacle, thelatching beams are squeezed inwardly, thereby allowing the latching lugsto move out of the recesses. The CPA/CLA includes two openings toreceive the ends of the latching beams when the CPA/CLA is in the closedposition. The latching beams cannot fit into the openings unless theconnector is properly seated and locked into the initiator receptacle.

The connector also includes a connector lock assurance (CLA) mechanismto ensure that the connector is locked into the initiator receptacle.The CLA includes two wedge members located to fit between each latchingbeam and an exterior surface of the connector body. When the CPA/CLAplate is pivoted into the closed position, the wedges are positionedbetween the latching beams and the connector body, thereby forcing thelatching beams outwardly to lock the connector into the initiatorreceptacle.

The CPA/CLA includes a latching mechanism to hold it in the closedposition onto the connector body. In the preferred embodiment, latchingfingers depend from the underside of the CPA/CLA plate to mate withsuitable lugs extending outwardly from the wall of the connector body.

One or more orientation keys may be provided on the connector body toorient the body properly in the initiator receptacle.

DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is cross-sectional side view of a squib connector in accordancewith the present invention;

FIG. 2 is a partial cross-sectional plan view of the squib connector ofFIG. 1;

FIG. 3 is a partial cross-sectional end view of the squib connector ofFIG. 1;

FIG. 4 is a side view of the squib connector of FIG. 1;

FIG. 5 is a further partial cross-sectional end view of the squibconnector of FIG. 1;

FIG. 6 is a cut-away side view of the squib connector of FIG. 1;

FIG. 7 is a top plan view of the squib connector of FIG. 1; and

FIG. 8 is a plan view of a box terminal and wire crimping device of thesquib connector of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The squib connector of the present invention is shown in FIGS. 1 through7. The connector includes a connector body 10 having a dependingcylindrical portion 12 sized to fit within an initiator receptacle 14 ofa squib 16. A pair of terminals or initiator pins 18 are anchored to thesquib 16 within the receptacle. A pair of box terminals 20 is locatedinternally of the connector body 10 to contact the initiator pins 18 forelectrical communication therewith when the connector is mounted withinthe squib receptacle.

The squib connector also includes a cover 22 and a connector positionassurance member and connector lock assurance or CPA/CLA 24 overlyingthe cover, discussed further below. A pair of wires 26 from thedeceleration sensor enter the connector body 10 through a space betweenthe cover 22 and the body 10. A wire crimping device 28 comprising aninsulation grip 30 and a wire grip 32 fixes each wire within the body.The wire crimping device 28 is preferably formed as a single piece withthe box terminal 20 via a suitable connecting member 34 to provide agood electrical communication path between the wires and the initiatorpins of the squib, as shown in FIG. 8. The wire crimping device and boxterminal are formed from a suitable conductive material such asberyllium copper grade 17410 available from Brush-Wellman of Cincinnati,Ohio. A ferrite or other inductive body 36 surrounds the wire crimpingdevice 28 to prevent stray signals from affecting the squib. A shortingclip 38 is provided in the base of the receptacle to provide a shuntacross the initiator pins when the connector is removed.

The connector body 10, cover 22, and CPA/CLA 24 may be formed from anysuitable nonconducting material capable of meeting the structuralrequirements of the squib connector. A plastic material, nylon 6/6,having 15 percent glass fiber reinforcement has been found to besuitable.

The connector of the present invention provides strain relief for thewires 26 entering the connector in two ways. Primary strain relief isprovided by two members 40, 42 depending from the cover 22 and a member44 extending from the connector body 10. The extending member 44 islocated generally between the two depending members 40, 42 andpreferably has a generally pointed or rounded end. The pointed orrounded end puts a kink or bend 46 in the wire when the wire issandwiched between the body 10 and the cover 22 in the closed position.Other means of forming a kink or bend in the wires may be employed. Forexample, two members could extend up from the body 10 in opposition toand laterally spaced from a single member depending from the cover 22.

Secondary wire strain relief is provided by forming the end 48 of thecover 22 adjacent the outer depending member with a curved surface. Thecurved end ensures that the wire does not bend sufficiently to cause abreak in the wire. Such breaks are particularly prone to occur due tohandling during manufacture or replacement.

Referring to FIG. 8, each box terminal 20 comprises a box formed, forexample, by a strip of a metal or other suitable conductive materialshaped into a box shape. The ends 50, 52 of the strip are fastened inany suitable manner. Each box is disposed in the connector body tosurround an associated initiator pin 18 when the connector is mounted inthe squib receptacle. One wall of each box also has a louver 54 formedtherein, as by punching out a section of the wall to provide athree-sided structure. The louver forms a portion of a secondaryterminal latch, discussed further below.

Each box terminal 20 further includes two contact beams 56 which arepreferably integrally formed with the box and are bent to extendupwardly within the box. When the connector is mounted within a squibreceptacle, the contact beams contact the initiator pins adjacent thefree ends thereof. Preferably, the contact beams are biassed inwardly,due, for example, to the spring-like flexibility of the material formingthe beams, to ensure good contact between the free ends and theinitiator pins.

Each contact beam is relatively flat at its base near its connectionwith the box and is curved near its free end 60 to wrap around theinitiator pin 18, as shown schematically in FIG. 8. FIG. 8 illustratesthe curved portion of the contact beam in continuous contact with theinitiator pin. In actuality, the contact beam contacts the initiator pinat discrete points. The curve provides at least two points of contactbetween each contact beam and its associated initiator pin. Thus, foreach box terminal, at least four points of contact are provided betweenthe terminal and the initiator pin.

A gold stripe is plated onto each contact beam at the area 64 where thebeam contacts the initiator pin. Gold is a good conductive material,thus improving the contact between the box terminal and the initiatorpin. Other conductive materials, such as silver, palladium, orsilver/palladium alloys, which can be plated or otherwise suitablydeposited onto the beam can be used.

A lubricating material is also provided on each contact beam below thegold stripe to reduce friction during insertion of the initiator pinbetween the two opposed beams, so that the initiator pin can be properlyseated between the beams for good contact with the gold stripes.Preferably, the lubricating material is formed from gold flashed ontothe beam. In prior art connectors, the lubricating material is atin/lead material. However, during insertion, the lubricating materialtends to get pushed up into the gold stripe area, impairing the contactbetween the gold stripe and the initiator pin. Thus, the lubricatingmaterial is preferably the same as the material forming the conductivestripe. Other materials, such as silver, palladium, or silver/palladiumalloys, which can be flashed or otherwise suitably deposited onto thebeams, can be used.

Each box terminal 20 is held within the connector body 10 by a primaryterminal latch 66 and a secondary terminal latch 68. The primary latchis formed by a pair of first arms 70 depending at a slight angle tocontact a top edge of the box of an associated box terminal 20. The topedge is the strongest part of the box terminal. Preferably, a shoulderis formed in the end of the first arm and is configured to seat againstthe top edge.

The secondary latch 68 is formed by a pair of second arms 72 depending,also preferably at a slight angle, to contact the end of the louver 54formed in one wall of the associated box terminals. The end of thesecond arm also has a shoulder formed therein and is configured to seatagainst the end of the louver.

The box terminal 20 is inserted into the connector body 10 by pushing itdown through the top. The box pushes the first and second arms 70, 72 tothe side as it is inserted. The arms snap back into the latchingposition once the box terminal has passed. Once in place, each boxterminal is held securely between the first and second terminal latchesand a floor 74 of the connector body. The combination of the primary andthe secondary terminal latches increases resistance to pulling theterminal out of the body. It will be appreciated that other latchingconfigurations are possible to retain the terminal in the body.

To keep out dust and moisture, the cover 22 is sized to fit over theareas in which the wire, wire crimping device, ferrite body, and boxterminals are disposed. The cover and the connector body are fastenedtogether, as by sonic welding or other suitable method, once the boxterminal and the wires have been inserted in the body.

The CPA/CLA 24 lies over the top of the cover 22 and extends beyond theedges of the cover. The CPA/CLA is hinged to the connector body 10 atthe rear end thereof. Preferably, the CPA/CLA includes a hinge pin 76integrally molded to the CPA/CLA to form a unitary structure. The hingepin fits within suitable recesses formed in the connector body toreceive the hinge pin.

The CPA comprises a connector position assurance mechanism to ensurethat the connector is properly positioned on the initiator pins. Thesquib receptacle includes two recesses 80 therein, best seen in FIGS. 3and 5, into which corresponding latching lugs 84 formed on the connectorbody 10 fit to retain the connector within the receptacle. Each latchinglug is located near the base of an associated latching beam 88 formed onopposed sides of the connector body. Each latching beam may be formed bycutting two parallel slits in the connector body and extending into thecylindrical portion which fits within the squib receptacle. The CPA/CLAincludes two openings 94 therein located to receive the ends of thelatching beams 88 when the CPA/CLA is in the closed position. Thelatching beams cannot fit into the openings unless the connector isproperly seated and locked into the squib receptacle.

The connector also provides a lock assurance mechanism (CLA) to ensurethat the connector is locked into the squib receptacle. To remove theconnector from the receptacle, the CPA/CLA is pivoted up, allowing thelatching beams 88 to be squeezed inwardly, thereby allowing the latchinglugs 84 to move out of the recesses 80 in the squib receptacle. Theconnector can then be lifted out of the receptacle. The CPA/CLA 24includes two depending wedge members 102 located to fit between eachlatching beam 88 and an exterior surface 90 of the connector body 10.When the CPA/CLA 24 is rotated into the closed position, the wedges 102are positioned between the latching beams and the connector body,thereby forcing the latching beams outwardly and preventing the latchingbeams from being squeezed inwardly. In this manner, the connector islocked into the squib receptacle. The connector cannot be removed untilthe CPA/CLA is rotated to an open position. As shown in FIGS. 4 and 6,the wedge members are curved to allow them to be rotated down into therespective spaces provided in the connector body. The surfaces of theconnector body may also be curved as needed to accommodate the wedgemembers.

The CPA/CLA 24 includes a latching mechanism to hold the CPA/CLA andcover in the closed position. In the preferred embodiment, latchingfingers 106 depend from an underside of the CPA/CLA to mate withsuitable lugs 110 extending outwardly from the wall of the connectorbody 10. Each latching finger includes an inwardly directed tab 114formed on an end thereof to fit beneath the associated lug when theCPA/CLA is in the closed position. The fingers are generallysufficiently resilient to allow the tabs to slip past the lugs duringrotation of the CPA/CLA to remove the connector. Other suitable latchingmechanisms can be used to hold the CPA/CLA in the closed position.

One or more orientation keys 118 may be provided on the connector bodyto orient the body properly in the squib receptacle. For example, a lugor pair of lugs may be provided extending from the outside of the bodyto fit within associated recesses formed in the squib receptacle. Othersuitable orientation devices may be provided.

The invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims.

I claim:
 1. A squib connector for an automotive air bag assembly havinga squib, the squib having a pair of terminal pins anchored thereto andextending upwardly in a squib connector receiving receptacle, said squibconnector comprising:a connector housing having a portion adapted tomate with the receiving receptacle of the squib; a terminal assemblydisposed within said connector housing for electrical communication withthe terminal pins of the squib; a latching assembly extending from saidconnector housing moveable from a latched position to a releasedposition, said latching assembly having a latching member thereonadapted to mate with a corresponding latch receiving member on the squibwhen said latching assembly is in the latched position; a connectorposition and lock assurance assembly comprising a pivoting memberhingedly connected to said connector housing for pivoting about an axisto and from a closed position against said connector housing and havingan opening therein located to receive said latching assembly when saidpivoting member is in the closed position, thereby ensuring saidlatching assembly is in the latched position.
 2. The squib connector ofclaim 1, wherein said connector position and lock assurance assemblyfurther comprises a wedge member depending from said pivoting member ata position to fit between said latching assembly and a surface of saidconnector housing to retain said latching assembly in the latchedposition.
 3. The squib connector of claim 1, wherein said latchingassembly comprises a pair of upwardly extending flexible latching beams.4. The squib connector of claim 1, wherein said pivoting member furtherincludes a latch mechanism to retain said pivoting member in the closedposition against said connector housing.
 5. The squib connector of claim1, wherein said connector housing comprises a connector body and a coverfixedly attached to said connector housing.
 6. The squib connector ofclaim 5, further comprising a wire strain relief assembly comprising aspace between said cover and said connector body sized to place a bendin a wire entering between said cover and said connector body.
 7. Thesquib connector of claim 5, further comprising a wire strain reliefassembly comprising a rounded end of said cover at a location where awire enters said connector housing.
 8. The squib connector of claim 1,wherein said terminal assembly comprises two pairs of opposed contactbeams disposed to contact the terminal pins of the squib, said opposedcontact beams having free ends curved to wrap around the terminal pins.9. The squib connector of claim 1, wherein said terminal assemblycomprises a pair of terminals having a box shape, a louver being formedin one wall of each of said box shapes, and further comprising a pair ofterminal latches disposed to contact said louvers to retain saidterminals in said connector housing.
 10. The squib connector of claim 1,wherein said terminal assembly comprises a pair of terminals having abox shape, and further comprising a pair of terminal latches disposed tocontact a top edge of each of said box shapes to retain said terminalsin said connector housing.
 11. The squib connector of claim 1, whereinsaid pivoting member is hingedly connected to said connector housing forpivoting by a hinge pin integrally formed with said pivoting member andreceived in a corresponding hinge pin receptacle formed in saidconnector housing.
 12. The squib connector of claim 1, wherein saidterminal assembly comprises two pairs of opposed contact beams disposedto contact the terminal pins of the squib, said beams having aconductive stripe of a conductive material deposited thereon and alubricating material deposited thereon below said conductive stripe andformed of said conductive material.
 13. The squib connector of claim 12,wherein said conductive material comprises gold, silver, palladium, or asilver/palladium alloy.